page_title: 103P/Hartley
section_title: 2010 Earth approach
hierarchical_section_title: 103P/Hartley / Discovery and orbit / 2010 Earth approach
caption_attribution_description: The close approach of 103P/Hartley to the Earth on 2010-Oct-20. The comet will come to perihelion (closest approach to the Sun) just 8 days later on 2010-Oct-28.
context_page_description: Comet Hartley 2, designated as 103P/Hartley by the Minor Planet Center, is a small periodic comet with an orbital period of 6.46 years. It was discovered by Malcolm Hartley in 1986 at the Schmidt Telescope Unit, Siding Spring Observatory, Australia. Its diameter is estimated to be 1.2 to 1.6 kilometres.
  Hartley 2 was the target of a flyby of the Deep Impact spacecraft, as part of the EPOXI mission, on 4 November 2010, which was able to approach within 700 kilometers of Hartley 2 as part of its extended mission. As of November 2010 Hartley 2 is the smallest comet which has been visited. It is the fifth comet visited by spacecraft, and the second comet visited by the Deep Impact spacecraft, which first visited comet Tempel 1 on 4 July 2005.
context_section_description: The comet passed within 0.12 AU (18,000,000 km; 11,000,000 mi) of Earth on 20 October 2010, only eight days before coming to perihelion (closest approach to the Sun) on 28 October 2010. From northern latitudes, during early November 2010, the comet was visible around midnight without interference from the Moon.
  Despite its current close passage by Earth's orbit, the comet is not yet a known source of meteor showers. However, that could change. Dust trails from the recent returns of 103P/Hartley 2 move in and out of Earth's orbit, and the 1979-dust trail is expected to hit in 2062 and 2068.
  After the 2010 perihelion passage, not accounting for nongravitational forces, Hartley 2 is estimated to come back to perihelion around 20 April 2017.
caption: Comet 103P passing within 0.12AU of Earth on 20 October 2010.[11]
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